How Common Is Sleep Apnoea in the UK?

Sleep apnoea is more common than many people realise, yet it remains one of the most under-diagnosed conditions in the UK. NHS estimates suggest around 1.5 million adults are affected, though the true figure is likely higher because a large proportion of cases are never formally identified. The condition causes repeated interruptions to breathing during sleep, leading to poor rest and a range of daytime symptoms. Understanding how widespread sleep apnoea is, who is at risk, and what signs to look for can help people seek timely assessment and appropriate treatment.

How common is sleep apnoea in the UK?

Around 1.5 million UK adults are estimated to have sleep apnoea, though this is widely considered an underestimate as many cases remain undiagnosed. Clinically significant OSA may affect 3% to 7% of the adult population.

Sleep apnoea is one of the most under-recognised chronic conditions in the UK. NHS estimates suggest that around 1.5 million adults in the UK are affected, though this figure is widely considered an underestimate because many cases are never formally diagnosed. The term covers a spectrum of disorders in which breathing repeatedly stops and starts during sleep, with obstructive sleep apnoea (OSA) being by far the most prevalent form. OSA occurs when the muscles of the throat relax excessively, causing the airway to narrow or close entirely, leading to brief but repeated interruptions in breathing throughout the night.

Population studies suggest that clinically significant OSA, defined by an apnoea-hypopnoea index (AHI) of five or more events per hour alongside daytime symptoms, may affect somewhere between 3% and 7% of the adult population; higher estimates arise when milder or asymptomatic cases are included.^[8][2] NICE guideline NG202 (Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s) sets out the UK diagnostic criteria and management framework for the condition.^[2][4] Central sleep apnoea, where the brain fails to send the correct signals to the breathing muscles, is considerably rarer and is often associated with underlying cardiac or neurological conditions.

Despite its prevalence, a substantial proportion of people with OSA have never received a formal diagnosis. Awareness campaigns and improved access to sleep studies have helped increase referral rates in recent years, but significant diagnostic gaps remain, particularly among women and younger adults whose presentations may differ from the classic pattern.

Who is most likely to develop sleep apnoea?

Obesity is the strongest modifiable risk factor for OSA, with additional risk from male sex, older age, large neck circumference, alcohol use and certain anatomical features such as a recessed jaw or enlarged tonsils.

Certain groups face a considerably higher risk of developing obstructive sleep apnoea, with excess body weight being the single strongest modifiable risk factor. Fat deposits around the neck and upper airway narrow the breathing passage during sleep, and NICE guideline NG202 recognises obesity as a primary driver of the condition. Men are diagnosed more often than women, with some large population studies suggesting a ratio of roughly two to three to one, though this gap narrows after the menopause, suggesting that hormonal factors play a protective role in younger women.^[10][11]

Age is also a significant contributor. The prevalence of OSA rises steadily from middle age onwards, partly because muscle tone in the throat decreases with age and partly because weight tends to increase over time. Other established risk factors include:

• A large neck circumference (screening tools such as STOP-Bang use thresholds of around 40 cm in women and 43 cm in men as indicators of increased risk; these are screening cut-offs, not diagnostic criteria)

• Anatomical features such as a recessed jaw, enlarged tonsils or adenoids, a narrow palate, or other craniofacial differences

• Nasal congestion or obstruction, whether from allergies, a deviated septum or chronic rhinitis

• Alcohol consumption, particularly in the evening, which relaxes throat muscles further

• Smoking, which causes upper airway inflammation

• A family history of sleep apnoea

• Type 2 diabetes and other metabolic conditions

• Neuromuscular conditions that affect upper airway muscle tone

Certain medical conditions, including hypothyroidism and acromegaly, are also associated with an increased risk. People with Down's syndrome have a particularly high prevalence of OSA due to anatomical and muscle-tone differences.^[9] Recognising these risk factors is important because early identification allows intervention before the condition causes significant cardiovascular or metabolic harm.

What are the signs that you might have sleep apnoea?

Loud snoring with witnessed breathing pauses and excessive daytime sleepiness are the hallmark signs of OSA. Other symptoms include unrefreshing sleep, morning headaches, poor concentration and nocturia.

Loud, persistent snoring accompanied by witnessed pauses in breathing are the most recognisable signs of obstructive sleep apnoea, though not everyone who snores has the condition and not everyone with OSA snores loudly. The pauses in breathing, which can last from a few seconds to over a minute, are often followed by a gasping or choking sound as the person partially wakes to restore airflow. A bed partner or family member is frequently the first to notice these episodes.

Daytime symptoms are equally important and are often what prompt people to seek medical advice. Excessive daytime sleepiness, sometimes severe enough to cause drowsiness while driving or during conversations, is a hallmark feature. Other common symptoms include:

• Waking with an unrefreshing sleep, regardless of how many hours were spent in bed

• Morning headaches, which may be related to overnight changes in blood oxygen and carbon dioxide levels

• Difficulty concentrating or memory problems during the day

• Irritability, low mood or anxiety

• Nocturia (waking repeatedly to urinate during the night)

• A dry mouth or sore throat on waking

• Reduced libido

In children, the signs can differ and may include restless sleep, bedwetting, behavioural difficulties, poor school performance, growth concerns and mouth breathing. If you or someone close to you notices several of these symptoms together, it is worth discussing them with a GP rather than attributing them solely to stress or a busy lifestyle.

Driving safety: If you experience excessive daytime sleepiness, you must not drive until the condition is assessed and adequately treated. The DVLA requires people with OSA who have excessive sleepiness to notify the DVLA and stop driving until a doctor confirms the condition is controlled.^[7] Full guidance is available in the DVLA document 'Assessing fitness to drive: a guide for medical professionals' under the respiratory disorders section. Untreated OSA carries meaningful risks for cardiovascular health, blood pressure and road safety, so early assessment is advisable.

How is sleep apnoea diagnosed on the NHS?

OSA is diagnosed using clinical assessment and a sleep study, usually a home-based test that calculates the apnoea-hypopnoea index (AHI). NICE NG202 classifies mild OSA as AHI 5 to 14, moderate as 15 to 29, and severe as 30 or above.

Sleep apnoea is diagnosed through a combination of clinical assessment and a sleep study, with the specific pathway depending on the severity of symptoms and local NHS service provision. A GP will typically take a detailed history, ask about snoring, witnessed apnoeas and daytime sleepiness, and may use a validated questionnaire such as the Epworth Sleepiness Scale to quantify daytime drowsiness. Blood pressure, body mass index and neck circumference are usually measured at this stage.

If OSA is suspected, the GP will refer the patient to a specialist sleep service or respiratory medicine department. NICE guideline NG202 supports the use of home-based sleep studies for most adults with suspected OSA, which has significantly reduced waiting times compared with in-laboratory polysomnography.^[4][6] Access to diagnostics and devices may vary depending on local NHS commissioning through Integrated Care Boards (ICBs). A home sleep test typically involves wearing a small device overnight that records:

• Airflow through the nose and mouth

• Oxygen saturation in the blood (via a finger probe)

• Chest and abdominal movement

• Heart rate

• Body position

The results are analysed to calculate the apnoea-hypopnoea index (AHI), which quantifies the number of breathing interruptions per hour of sleep. In line with NICE NG202, an AHI of 5 to 14 is classified as mild, 15 to 29 as moderate, and 30 or above as severe OSA. Full in-laboratory polysomnography, which also records brain activity, eye movements and muscle tone, is reserved for complex cases or where a home study is inconclusive. Diagnosis is made by a specialist who considers both the AHI and the clinical picture, including the presence and severity of daytime symptoms.

What treatments are available and how well do they work?

CPAP therapy is the most effective first-line treatment for moderate to severe OSA, reducing sleepiness, lowering blood pressure and improving cognitive function. Mandibular advancement devices, positional therapy and lifestyle changes are alternatives for milder cases or CPAP intolerance.

Continuous positive airway pressure (CPAP) therapy is the most effective treatment for moderate to severe obstructive sleep apnoea. NICE guideline NG202 and NICE technology appraisal TA139 both recommend CPAP as the first-line intervention for these groups.^[4][5] CPAP works by delivering a continuous stream of pressurised air through a mask worn during sleep, which acts as a pneumatic splint to keep the upper airway open and prevent the collapse that causes apnoeas. Evidence consistently shows that regular CPAP use reduces daytime sleepiness, lowers blood pressure, improves cognitive function and reduces the risk of road traffic accidents related to drowsiness.^[12][13] Adherence is the key determinant of benefit, and NHS sleep services typically offer follow-up support and mask-fitting reviews to help patients adapt. Access to CPAP devices and ongoing support is subject to local NHS commissioning through ICBs.

For mild OSA, or for people who cannot tolerate CPAP, several alternative approaches are available:

• Mandibular advancement devices (MADs): custom-fitted dental appliances that hold the lower jaw slightly forward to widen the airway. NICE NG202 recommends these as an alternative for mild to moderate OSA or where CPAP is not tolerated.^[4]

• Positional therapy: for people whose apnoeas occur predominantly when lying on their back, devices or techniques that encourage side-sleeping can be effective.

• Lifestyle modification: weight loss, reducing alcohol intake, stopping smoking and treating nasal congestion can all reduce OSA severity and, in mild cases, may be sufficient on their own.

• Surgery: procedures such as tonsillectomy or adenoidectomy are considered in selected cases, particularly in children or adults with specific anatomical obstruction, following specialist assessment.

Weight-management support is an important component of care for many people with OSA, and NHS services may refer patients to structured programmes. For those exploring weight-management options more broadly, Bolt Pharmacy is a GPhC-registered UK online pharmacy offering online weight-management consultations, with prescriber review and pharmacist support; any prescription medicine would only be provided where clinically appropriate following a consultation. Treatment choice should always be guided by a specialist, taking into account OSA severity, individual anatomy, comorbidities and patient preference.

Scientific References

1. Sleep apnoea.
2. Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s (NG202).
3. Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s (NG202) – Terms used in this guideline.
4. Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s (NG202) – Chapter 1: Obstructive sleep apnoea/hypopnoea syndrome.
5. Continuous positive airway pressure for the treatment of obstructive sleep apnoea/hypopnoea syndrome (TA139).
6. Home-testing devices for diagnosing obstructive sleep apnoea hypopnoea syndrome (DG62).
7. Excessive sleepiness and driving.
8. Incidence and prevalence of obstructive sleep apnoea and narcolepsy in the UK.
9. Prevalence and predictors of obstructive sleep apnoea in children with Down syndrome.
10. Gender and obstructive sleep apnea syndrome, part 2: mechanisms. Sleep.
11. Expert consensus on the diagnosis and treatment of obstructive sleep apnea in women.
12. Continuous positive airways pressure for obstructive sleep apnoea in adults (Giles et al.).
13. Continuous positive airways pressure for obstructive sleep apnoea in adults (Lim et al.).

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